Reference throughout this specification shall now be made to the present invention being used in fluid transfer applications. However, it should be appreciated by those skilled in the art that the present invention may be employed in other applications, not necessarily being just the transfer of fluid. For example, the present invention may be employed to allow the transfer of a fine particulate material such as a powder.
Valves are used in numerous applications to control the flow of a fluid from one point or container to another point or container. Valve assemblies are preferably manufactured from plastic materials as this reduces manufacturing cost and time, allowing a large number of valve assemblies to be produced with a high degree of conformity in shape and quality.
When moulding plastic material into the components of a valve it is desirable that the number of individual parts employed is minimised. If the majority of a valve assemblies components could be moulded from one single component this is of great advantage.
As the number of separate components employed increases so does:
a) the number of separate tools required in the manufacturing process, increasing the capital start up costs for the manufacturer and associated manufacturing costs, and PA1 b) a slow down in the manufacturing process time as a large number of components need to be firstly formed and finished and then assembled together to form the finished product, and PA1 c) an increase in the amount of waste material generated in the manufacturing process as a consequence of the increase in the number of parts formed. PA1 (a) forcing a valve head against an engagement element, and PA1 (b) deforming at least a portion of the valve head against the engagement element, and PA1 (c) creating a fluid path through the valve assembly past the deformed valve head.
For example, in one instance when a valve assemble must include a separate latch component the cost of manufacturing and its associated process time increases.
In some instances where separate components are required in a valve assembly, collapsible cores within the moulds are required. These collapsible cores enable undercuts to be formed within the components manufactured, and are typically used to construct threads on bottles. Each of the cores required are expensive to purchase and to also fit into the manufacturing machinery.
The number of parts employed in a valve assembly can also be minimised by using "snap fit" assembly techniques. Components can be retained in place in the valve assembly by using complimentary shapes which when pushed or `snapped` together will hold the components in place.
A valve which could be manufactured from plastic material and which also could be assembled as a "snap fit" without any additional adhesives or attachment components would be of great advantage to the manufacturer. A "snap fit" assembly process again reduces the number of components of the valve and hence will also reduce the manufacturing time associated with assembling the valve.
A valve that solved any or all of the above problems would be a great advantage over the prior art. Specifically a valve which could be manufactured from plastic materials, which incorporated a minimum number of separate components and which could be "snap fit" assembled together would be of great advantage over the prior art.
It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.
Further aspects and advantages of the present invention will become apparent from the ensuing description that is given by way of example only.